Alpha hemolysin of E. coli induces hemolysis of human erythrocytes independently of toxin interaction with membrane proteins.
Biochimie
; 216: 3-13, 2024 Jan.
Article
en En
| MEDLINE
| ID: mdl-37820991
ABSTRACT
Alpha hemolysin (HlyA) is a hemolytic and cytotoxic protein secreted by uropathogenic strains of E. coli. The role of glycophorins (GPs) as putative receptors for HlyA binding to red blood cells (RBCs) has been debated. Experiments using anti-GPA/GPB antibodies and a GPA-specific epitope nanobody to block HlyA-GP binding on hRBCs, showed no effect on hemolytic activity. Similarly, the hemolysis induced by HlyA remained unaffected when hRBCs from a GPAnull/GPBnull variant were used. Surface Plasmon Resonance experiments revealed similar values of the dissociation constant between GPA and either HlyA, ProHlyA (inactive protoxin), HlyAΔ914-936 (mutant of HlyA lacking the binding domain to GPA) or human serum albumin, indicating that the binding between the proteins and GPA is not specific. Although far Western blot followed by mass spectroscopy analyses suggested that HlyA interacts with Band 3 and spectrins, hemolytic experiments on spectrin-depleted hRBCs and spherocytes, indicated these proteins do not mediate the hemolytic process. Our results unequivocally demonstrate that neither glycophorins, nor Band 3 and spectrins mediate the cytotoxic activity of HlyA on hRBCs, thereby challenging the HlyA-receptor hypothesis. This finding holds significant relevance for the design of anti-toxin therapeutic strategies, particularly in light of the growing antibiotic resistance exhibited by bacteria.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Toxinas Biológicas
/
Proteínas de Escherichia coli
Límite:
Humans
Idioma:
En
Revista:
Biochimie
Año:
2024
Tipo del documento:
Article
País de afiliación:
Argentina